Making sustainability a default option can have very powerful results, research has found Photograph: Alamy

"Think globally, act locally" urges individuals to consider how switching to local might impact the environment. Through this trade-off, which might come at a relatively small cost (for example in money, effort, or time) and aggregated large-scale benefits (for example, reducing global CO2 emissions), the hope is that people will make choices that will reduce the severity of a wide variety of global environmental problems.

Among a wide range of possible choices, individuals are encouraged to conserve energy and natural resources at home and in the workplace, by making changes to their travel and commuting habits, and by choosing foods and other goods that are sourced from environmentally-sensitive production practices.

But here's the catch. Some four decades after the concept of think globally, act locally was first introduced, studies suggest that people still fail to make even small changes in their behaviour to address the negative environmental consequences of their actions.

And, we observe this trend in spite of the fact that studies also suggest that people the world over are becoming increasingly concerned about the health of the natural environment. So, while think globally, act locally still has appeal in certain professional circles – among environmental educators, for example – the concept receives scant attention in environmental policy circles.

So, what if we told you that people could achieve the lofty goals of think globally, act locally without having to pull on any policy levers or without having to aggressively pursue initiatives aimed at environmental education? Not only is this possible, it's really quite easy.

In the preceding pieces in this series, I wrote about the decision making shortcuts we routinely apply during decision making, and how these can lead to systematic biases. I also wrote about how theses biases could be overcome using techniques like structured decision making. In the case of meeting sustainability objectives in the absence of policy shifts, however, the trick is to exploit our judgmental biases by re-engineering the environment in which decisions get made.

Much of the work devoted to this approach falls under the umbrella of the somewhat unfortunately named "libertarian paternalism", also known as "nudging". In one of the best examples of a nudge (and an unintentional one to boot), researchers showed that by making driving license applicants organ donors by default (in other words, to choose to not being an organ donor, they'd have to tick a box on their applications to opt out of the program), organ donation rates could be as much as 20 times higher than in situations where the reverse was true (ie applicants were not donors by default and would have to opt in by ticking a box if they wanted to participate).

This natural experiment illustrates how powerful default options can be. We also know from other research that people have a hard time making changes when it comes to decisions. Change is a psychologically difficult thing to do, and frankly, it's often easier to stick with what we have, what we know, or what seems familiar. Indeed, we have a name for this: it's called the status quo bias.

In our own research, we've been able to take advantage of the status quo bias in an effort to promote more sustainable decisions and behaviours at the local level (ie in line with think globally, act locally). For example, by making "low flow" the default setting on multi-flow showerheads in luxury hotels, we were able to demonstrate that most guests rarely turn their showers to full power, thereby saving water and the energy required to heat it.

In cafeterias, by making sustainably sourced foods an "implied default" (in that they could be chosen by diners, and served by the wait staff most quickly) as compared to less sustainable options that required a short wait (of just seconds more, rather than minutes), we were able to easily shift most (upwards of 80%) consumer's choices in the direction of more sustainable options.

The trick when it comes to nudges is to not restrict options. People must always be allowed to choose an alternative, even unsustainable if they wish, option. And, they must be allowed to choose it without much in the way of additional effort on their part. But the good news is that science shows, in spite of the relative similarities in effort required for both kinds of choice, defaults (or implied defaults) often carry the day in decision making.

Getting these defaults – and by extension, the nudges – right, and matching them to sustainable outcomes can be a little tricky. But, at the same time, it's not as hard as you might think. And, in terms of the outcomes for promoting sustainable behaviours, nudges are well worth the effort.

Dr. Joe Arvai is Svare chair in applied decision research for the Institute for Sustainable Energy, Environment, and Economy and Haskayne School of Business at The University of Calgary. Follow Joe on Twitter at @DecisionLab.

Dr Victoria Campbell-Arvai is a member of the Institute for Sustainable Energy, Environment, and Economy at the University of Calgary.